如何在Postback事件上读取ADO.NET实体数据模型对象中的特定字段 [英] How to read a specific field in ADO.NET Entity Data Model Object on Postback event

问题描述

我有一个从数据库中填充的下拉列表：



控制器

I have a dropdownlist that is populated from a database as:

Controller

PayrollDb pdb = new PayrollDb ();
var addBranchGui = new branch();
addBranchGui.BranchTypes = new SelectList(pdb.branchtypes,"Id", "Type");

查看

View

<p>Branch Type:@Html.DropDownListFor(x => x.BranchType, Model.BranchTypes, "Choose an option")</p>

此代码正确填充下拉列表。当用户在下拉列表中选择一个选项并提交表单并且我在[HttpPost操作方法上捕获输入数据并将其插入到数据库表中时，出现问题时，当我想要类型时它就会插入Id字段要插入的字段。



我可以理解，在Postback事件中，浏览器正在读取Id字段。有人可以指导我如何命令浏览器给我类型字段，以便我可以将其插入数据库。

This codes correctly populates the dropdownload list. Problem arises when user selects an option in the dropdownlist and submits the form and I catch the input data on [HttpPost action method and insert it into a database table, it is the "Id" field that gets inserted when I want the "Type" field to be inserted.

I can understand that on Postback event, browsers is reading "Id" field. Can someone please guide me how I can command the browser to give me the "Type" field so I can insert that into database.

推荐答案

在 SelectList中构造函数，您指定 Id 作为下拉列表的数据值字段。

In the SelectList constructor, you are specifying Id as the data value field for the dropdown.

addBranchGui.BranchTypes = new SelectList(pdb.branchtypes,"Id", "Type");

所以它会像这样渲染下拉菜单

So it will render the dropdown like this

<select name="BranchType">
   <option value="2">HeadOffice
   <option value="4">Branch
</option></option></select>

所以改为使用 Type 作为 datavalue 字段。

So change it to use Type as the datavalue field.

addBranchGui.BranchTypes = new SelectList(pdb.branchtypes,"Type", "Type");

这将呈现一个SELECT元素具有相同值的选项值和选项文本

This will render a SELECT element with same value for the option value and the option text

<select name="BranchType">
   <option value="HeadOffice">HeadOffice
   <option value="Branch">Branch
</option></option></select>

现在当用户发布表单后，您将获得BranchType字段中的文本值（类型）。

Now when user posts the form, you will get the text value(the type) in BranchType field.

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